1. To force out or to remove, as from a place or position; to banish: Timothy was being very disobedient in class, so Mrs. Smart ousted him out of the classroom and sent him to the principal's office!
2. To remove and to be succeeded by someone else or something else: The computer has ousted the electric typewriter, but first the electric typewriter ousted the manual, old-fashioned typewriter.
4. Etymology: existing since about 1420, from Anglo-French oster (1292), from Old French oster, "put out, keep off, remove, avert"; from Latin obstare, "to stand opposite to, to block, to hinder"; from ob-, "against" + stare, "to stand".